A reciprocity cry for help.

[ki6mf]

At New England School of Photography we use this table as a starting place for black and white. I think that HP 5, the only film i shoot, can handle a 1 second exposure without going to the table. You should test to be sure.


Meter Reading Increase Time to:
1 Second 2 Seconds
2 Seconds 4 Seconds
4 Seconds 10 Seconds
8 Seconds 25 Seconds
15 Seconds 1 Minute 10 Seconds
30 Seconds 3 Minutes 10 Seconds
1 Minute 9 Minutes
2 Minute 22 Minutes
4 Minute 48 Minutes
8 Minute 1 Hour 30 Minutes
__________________
Wally Brooks

Everything is Analog!

[Doremus Scudder]

Mandoman7,

We're getting a bit off-topic here, but you bring up an interesting point about using reciprocity failure intentionally. I often use the contrast increase achieved by long exposures instead of expansion developing. I think it has a different character. Stopping down to get a longer exposure time or using a neutral-density filter can get you into the three-doubling range, which gives you about N+1 at normal developing times.

Wally,

The table you give seems to be for a different film than the FOMA 100. Using these times for the Foma film would likely underexpose. Each film has it's own reciprocity characteristics; one cannot reliably apply data from one film to another.

Best to all,

Doremus Scudder

[mandoman7]

Mandoman7,
I often use the contrast increase achieved by long exposures instead of expansion developing. I think it has a different character.
Best to all,

Doremus Scudder

Agreed. You can keep the mid and high tones in their proper relationship while completely dropping out the dark areas. Very useful in some contexts.

JY

[77seriesiii]

Mandoman7,

your comment falls in line with where I am going with trying to understand reciprocity. I understand what you are saying with testing and eliminating/identifying most idiosyncrasies of the film used, in my case the fomapan 100. Once a solid understanding of how it reacts in the reciprocity range and using consistent developing techniques (same developer otherwise another variable is introduced) I can exploit reciprocity and use the behavior to create something. I dont know what something is but when I create it more than once consistently and intentionally than it could be something.

./e